Need help reducing weight

[Walski]

I just started tilling my bow and it's 64" NTN, the wood is yew and I need to reduce a lot more wood in order to get it down to about 60#.   You can see from the photos of each limb, that I'll need to reduce more heartwood, right now I am about 50/50 sap/heart.
Where do I go from her?

[Digital Caveman]

Can you reduce width, or take a ring off the back?

[Pat B]

I would reduce the sapwood. You only need 1/4" to 3/8" of sapwood.

[ssrhythm]

I notice that you have a really slack tillering string on there.  Are you measuring your weight with the slack string?  I ask this...and it may seem obvious, but it is something that I overlooked despite understanding the physics of string angle and stacking...but I ask it because I made three very underweight bows due to measuring poundage at brace height with a slack tillering string.  I figured I'd get the bow to the weight I was after at brace height and then reduce wood from there.  I'd hit 58# at brace height with good bend, I'd cut in nocks and make a string for the bow, I'd string the bow, and I'd be dumbfounded that my bow was already below my target weight at 27' draw.  I finally stopped and thought about everything and realized that I was seeing 58# at brace height because I was pulling to brace height with my slack string just like your bow is in the picture.  The string angle was approaching 90 degrees and thus I was getting horrible stack and a very inaccurately high measure of draw weight at brace height. 

[mmattockx]

The string angle was approaching 90 degrees and thus I was getting horrible stack and a very inaccurately high measure of draw weight at brace height.

Badger (I think it was) has talked about this. If you are using a slack string and pulling to, say, 20" then the weight you get is close to the weight you would see with a proper length string at 20". As long as you are aware of this effect it can be used to judge what weight your bow is at out towards your target draw length well before you get there.


Mark

[ssrhythm]

Good to know.  All I know is that I felt like a complete DA once I realized what I was doing...and that I had repeated the same mistake expecting different results!

[Del the cat]

+1 on everytging said already!
Reduce the sapwood to an even 3/16" or so, try to do it evenly (spokeshave) don't be obsessive about following a ring, it's not necessary with Yew, but it looks nice of course.
Try and keep any violations showing as lines running along the bow, or gently feathered.
You can taper it a bit and leave extra near the grip if necessary. I reckon 50/50 is fine but I don't like to reduce the heartwood to much less than 50/50.
"slack" string should only just be long enough to get it on the bow, so it only hangs down about 6"
Del

[bownarra]

It is bending too much in the inner limbs, especially the right one. Do not touch the inners for a while. Get the mid limbs and outers moving more.
The tillering string should tight to the belly before bending.  A long string doesn't show the true, braced bend. The tips will look stiff. That siad yours are still too stiff!